This invention relates to attachment apparatus for attaching a tire mat to the circumference of a tired wheel. It will be understood that a tire mat is a mat for attachment to the circumference of a tired wheel in order to increase the grip of the wheel relative to the ground in conditions of snow, ice or mud or in other conditions in which normal tires do not provide enough grip to transmit sufficient traction forces to enable the vehicle to be driven.
In British Patent Specification No. 2,135,252 there is described a tire mat of the kind comprising a flexible mat having a plurality of resilient gripping members formed integrally with the mat on one surface of the mat. The mat is secured around the outside of the tired wheel so that these gripping members extend outwardly. There are also resilient projections formed integrally with the mat on the other surface of the mat, which, in use, engage in grooves formed by the treads of the tire. Each of the gripping members on one side of the mat has one of the projections aligned opposite thereto on the other side of the mat. The tire mat described is particularly efficient in the transmission of traction forces in conditions including snow, ice and mud, and is also usable at moderate speeds on metalled roads without damage to the tire or to the road surface. However, the efficiency of the mat is dependent upon secure fastening to the wheel.
There are many tire mat designs in existence, though few approach the effectiveness of the mat just described, and many systems and apparatus have been proposed for attaching and securing the mats in place on a wheel. In some instances chains or wires are used to secure mats, and, although these are strong, they often do not reliably remain tight, thus allowing the mat to slip out of position, and are often complex to mount and remove. Other attachment systems are relatively weak, and are prone to breakage. In many cases, the procedures for fitting tire mats are complicated, and some require skill or strength. Also, some require access to the inside of the wheel, which is often dirty and wet, when the mat is to be fitted. Some include fastenings which must be secured on the inside of the wheel in positions which cannot be seen, and which therefore have to be manipulated by feel.
It is the object of this invention to provide attachment apparatus for a tire mat which is reliable, strong and secure in use, and which can be simply fitted without risk of undue soiling of clothes or hands.